Actually, Grand Turismo 4 supported 1080i for the PS2. "The game looks stunning and with the 480p and 1080i modes for the lucky HDTV owners out there it gets even better."---IGN
Link:
http://ps2.ign.com/articles/589/589617p1.html
Remember, there was no reason for gamers to purchase HDTVs last gen, 99% of games supported 480p only.
If Nintendo is successful at the moment, it’s because they are good, and I cannot blame them for that. What we should do is try to be just as good.----Laurent Benadiba